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<title>C++ Implementation (Using the GNU Compiler Collection (GCC))</title>

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Next: <a href="C-Extensions.html" accesskey="n" rel="next">Extensions to the C Language Family</a>, Previous: <a href="C-Implementation.html" accesskey="p" rel="prev">C Implementation-Defined Behavior</a>, Up: <a href="index.html" accesskey="u" rel="up">Introduction</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html" title="Index" rel="index">Index</a>]</p>
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<h2 class="chapter" id="C_002b_002b-Implementation_002dDefined-Behavior"><span>5 C++ Implementation-Defined Behavior<a class="copiable-link" href="#C_002b_002b-Implementation_002dDefined-Behavior"> &para;</a></span></h2>
<a class="index-entry-id" id="index-implementation_002ddefined-behavior_002c-C_002b_002b-language"></a>

<p>A conforming implementation of ISO C++ is required to document its
choice of behavior in each of the areas that are designated
&ldquo;implementation defined&rdquo;.  The following lists all such areas,
along with the section numbers from the ISO/IEC 14882:1998 and ISO/IEC
14882:2003 standards.  Some areas are only implementation-defined in
one version of the standard.
</p>
<p>Some choices depend on the externally determined ABI for the platform
(including standard character encodings) which GCC follows; these are
listed as &ldquo;determined by ABI&rdquo; below.  See <a class="xref" href="Compatibility.html">Binary
Compatibility</a>, and <a class="uref" href="https://gcc.gnu.org/readings.html">https://gcc.gnu.org/readings.html</a>.  Some
choices are documented in the preprocessor manual.
See <a data-manual="cpp" href="https://gcc.gnu.org/onlinedocs/cpp/Implementation_002ddefined-behavior.html#Implementation_002ddefined-behavior">Implementation-defined
behavior</a> in <cite class="cite">The C Preprocessor</cite>.  Some choices are documented in
the corresponding document for the C language.  See <a class="xref" href="C-Implementation.html">C Implementation-Defined Behavior</a>.  Some choices are made by the library and operating
system (or other environment when compiling for a freestanding
environment); refer to their documentation for details.
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<li><a href="Conditionally_002dsupported-behavior.html" accesskey="1">Conditionally-Supported Behavior</a></li>
<li><a href="Exception-handling.html" accesskey="2">Exception Handling</a></li>
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